Huawei Quidway NetEngine80E Configuration Manual page 796

HUAWEI NetEngine80E/40E Router
Configuration Guide - IP Routing
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Issue 02 (2014-09-30)
The BGP view is displayed.
3. Run:
ipv4-family unicast
The IPv4 unicast address family view is displayed.
4. Run:
peer { ipv4-address | group-name } allow-as-loop [ number ]
The local AS number is allowed to repeat in the AS_Path attribute.
Generally, a BGP device checks the AS_Path attribute of a route sent from a peer. If
the local AS number already exists in the AS_Path attribute, BGP ignores this route
to avoid a routing loop.
In some special applications, you can use the peer allow-as-loop command to allow
the AS_Path attributes of routes sent from the peers to contain the local AS number.
You can also set the number of times the local AS number is repeated.
Configure BGP not to compare AS_Path attributes of routes in the route selection process.
1. Run:
system-view
The system view is displayed.
2. Run:
bgp { as-number-plain | as-number-dot }
The BGP view is displayed.
3. Run:
ipv4-family unicast
The IPv4 unicast address family view is displayed.
4. Run:
bestroute as-path-ignore
BGP is configured to ignore AS_Path attributes of routes during route selection.
Configure a fake AS number.
Generally, a device supports only one BGP process. This means that a device supports only
one AS number. If AS numbers need to be replaced during network migration, you can run
the peer fake-as command to set a fake AS number for a specified peer to ensure smooth
network migration.
1. Run:
system-view
The system view is displayed.
2. Run:
bgp { as-number-plain | as-number-dot }
The BGP view is displayed.
3. Run:
peer { ipv4-address | group-name } fake-as { as-number-plain | as-number-
dot }
A fake AS number is configured.
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8 BGP Configuration
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